Investors & landlords

it depends.  When you enter the asset and it has not been entered on your return before, then you should put the date placed in service and the date you acquired it.  They would be the same if it was immediately placed in service (2019).  Do not use a date in 2023. 

The prior depreciation should be automatically calculated in TurboTax and this will be the number you will use on your Form 3115. Do not use the current year's depreciation number.

Once you have the Form 3115 completed, you should enter the prior depreciation as 'Other expense' and describe it as Form 3115 Method or something similar.  The depreciation is easily calculated for you to compare by using the 27.5 year chart (see below for your convenience).